ZCS 7 statistics stale - zmrrdfetch bug?

Hi everybody,

I'm starting a new thread since most of the similar problems seem to have been detected on previous versions of ZCS.

I'm using ZCS 7 Ubuntu 64 and my statistics are stale. The behaviour of the server is somewhat similar to this thread but persists on ZCS7.
What works:
1) General stats: "advanced stats" (except zmmtastats and zmstatuslog)
1.1) Message count, message volume and av/as activity do show up for last 30, 60 and 365 days but data is inaccurate.
2) Site specific stats: disk stats, sessions, mailbox quotas.

IMPORTANT: While trying to fix this issue, i've replaced /opt/zimbra/libexec/zmrrsfetch with the second file provided on bug 41301 which is also attached to this post. Before that, none of the stats were working.